Methods are disclosed for removing alkali metal iodide from concentrated aqueous alkali metal chloride solutions using ion retardation resins. The methods are suitable for solutions comprising substantially more than 1 ppm iodide and greater than 100 g/l alkali metal chloride and can remove the iodide to levels below 1 ppm. To effect removal, the pH of the solution is adjusted to be less than about 10 and is then flowed through a separation bed comprising the resin in a series of loading and elution cycles. The method is particularly useful for removing iodide impurity from the concentrated feed brine used in chloralkali electrolysis.

A process for manufacturing an aqueous sodium chloride solution and the use of such solution for the manufacturing of crude sodium bicarbonate from SOLVAY ammonia process or for the manufacturing of soda ash, comprising the steps of: a) dispersing a first solid material comprising sodium chloride, sodium carbonate, and sodium sulfate, and a second solid material comprising calcium chloride in an aqueous liquid to produce an aqueous medium; b) subjecting the aqueous medium to clarification to produce a clarified aqueous medium; and c) recovering the clarified aqueous medium as aqueous sodium chloride solution; wherein a weight L/S ratio between the weight of the aqueous liquid used to produce the aqueous medium and the total weight of the first solid material and the second solid material is in the range of from 0.7 to 3.5.

A side stream subsystem can be used to remove impurity species from the recirculating alkali metal chloride solution in certain electrolysis systems. Silicon and/or aluminum species can be removed via precipitation after introducing an alkali metal hydroxide and magnesium chloride in a side stream line in the subsystem. The invention can allow for a substantial reduction in raw material and capital costs.

A side stream subsystem can be used to remove impurity species from the recirculating alkali metal chloride solution in certain electrolysis systems. Silicon and/or aluminum species can be removed via precipitation after introducing an alkali metal hydroxide and magnesium chloride in a side stream line in the subsystem. The invention can allow for a substantial reduction in raw material and capital costs.

The invention relates to chemical technology pertaining to mineral salts and can be used in the chemical industry. A process for producing sodium bromide from a bromide-containing polycomponent hydromineral feedstock includes: two-stage oxidation of bromide ions using gaseous chlorine during acidification of a brine: air desorption of elementary bromide: absorption of same using a cooled solution of sodium bromide: and reduction using ammonia in the presence of sodium hydroxide. The resulting concentrate of sodium bromide is evaporated until crystals are formed. The sodium bromide crystals are dried and a mother liquor is used to produce a solution of sodium bromide as a commercial product.

The invention relates to chemical technology pertaining to mineral salts and can be used in the chemical industry. A process for producing sodium bromide from a bromide-containing polycomponent hydromineral feedstock includes: two-stage oxidation of bromide ions using gaseous chlorine during acidification of a brine: air desorption of elementary bromide: absorption of same using a cooled solution of sodium bromide: and reduction using ammonia in the presence of sodium hydroxide. The resulting concentrate of sodium bromide is evaporated until crystals are formed. The sodium bromide crystals are dried and a mother liquor is used to produce a solution of sodium bromide as a commercial product.

The present invention provides a process for separating iodine from a NaCl brine, comprising the following steps: (a) providing said NaCl brine containing iodide, (b) adjusting the pH of said NaCl brine to be no greater than 1.5, (c) adding oxidizing agent, such as chlorine containing oxidizing agent, to said NaCl brine resulting from step (b) to obtain an oxidation-reduction potential in said NaCl brine of from 560 mV to 925 mV, the combination of said pH of no greater than 1.5 and oxidation-reduction potential of 560 mV to 925 mV resulting in the formation of an iodine-chlorine anionic complex, and (d) contacting nonionic adsorption resin and said NaCl brine from step (c) one with the other to adsorb said iodine from this brine, to obtain as a result thereof NaCl brine wherein the iodine content therein is preferably no greater than 100 ppbw, more preferably no greater than 10 ppbw.

Processes and apparatus for purifying brine are provided including (1) providing an aqueous brine solution comprising one or more inorganic salts and one or more organic compounds and (2) conducting at least one unit operation for removing organic compounds from the brine solution to obtain a purified brine solution.

Processes and apparatus for purifying brine are provided including (1) providing an aqueous brine solution comprising one or more inorganic salts and one or more organic compounds and (2) conducting at least one unit operation for removing organic compounds from the brine solution to obtain a purified brine solution.

Systems and methods for treatment of an effluent stream are disclosed. In an aspect, a system can comprise an input configured to receive a brine solution, a purification component in communication with the input and configured to receive the brine solution therefrom, the purification component comprising activated carbon, wherein the brine solution is caused to pass through the activated carbon to produce a purified solution, and an output in communication with the purification component to receive the purified solution therefrom.